Concentration of native point defects in Si single crystals at high temperatures

1990 ◽  
Vol 41 (15) ◽  
pp. 10741-10743 ◽  
Author(s):  
Yasumasa Okada
Keyword(s):  
Single Crystals ◽  
High Temperatures ◽  
Point Defects ◽  
Native Point Defects

High frequency ESR of native point defects in beryllium doped c-BN single crystals

2004 ◽  
Vol 201 (11) ◽  
pp. 2591-2598 ◽  
Author(s):  
E. Goovaerts ◽  
S. V. Nistor ◽  
D. Ghica ◽  
T. Taniguchi
Keyword(s):  
Single Crystals ◽  
Point Defects ◽  
High Frequency ◽  
Native Point Defects

The Agglomeration of Point Defects in Transition Metal Monoxides

1986 ◽  
Vol 82 ◽  
Author(s):  
E. Gartstein ◽  
M. Radler ◽  
T. O. Mason ◽  
J. B. Cohen
Keyword(s):  
Electrical Properties ◽  
Transition Metal ◽  
Single Crystals ◽  
High Temperatures ◽  
Point Defects ◽  
Absorption Edge ◽  
Defect Structure ◽  
Diffuse Scattering ◽  
Theoretical Work ◽  
Cluster Calculations

ABSTRACTRecent results on the diffuse scattering from single crystals of Fe1−xO at high temperatures reveal that the defect structure is in striking agreement with embedded cluster calculations by Ellis et al. The dominant defect is an imperfect 7:2 cluster. Mixtures of this and a larger complex (13:4) can explain the electrical properties. XANES studies of this oxide are in agreement with Ellis' theoretical work. However, in both FOx and MnxO it is not possible to use the shift of the cation K absorption edge to characterize valence. In fact in the latter case the shift passes through a minimum, perhaps indicating the onset of clustering.

Effect of Mn3+ doping on crystal structure, point defects, and optical properties in green Ca3(VO4)2 single crystals

2021 ◽  
pp. 111300
Author(s):  
Galina M. Kuz’micheva ◽  
Liudmila. I. Ivleva ◽  
Irina A. Kaurova ◽  
Evgeny V. Khramov ◽  
Victor B. Rybakov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Single Crystals ◽  
Point Defects

scholarly journals The impact of point defects in n-type GaN layers on thermal decomposition of InGaN/GaN QWs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mikolaj Grabowski ◽  
Ewa Grzanka ◽  
Szymon Grzanka ◽  
Artur Lachowski ◽  
Julita Smalc-Koziorowska ◽  
...  
Keyword(s):  
Quantum Wells ◽  
High Temperatures ◽  
Point Defects ◽  
X Ray Diffraction ◽  
Helium Ions ◽  
X Ray ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
The Impact ◽  
Ingan Quantum Wells

AbstractThe aim of this paper is to give an experimental evidence that point defects (most probably gallium vacancies) induce decomposition of InGaN quantum wells (QWs) at high temperatures. In the experiment performed, we implanted GaN:Si/sapphire substrates with helium ions in order to introduce a high density of point defects. Then, we grew InGaN QWs on such substrates at temperature of 730 °C, what caused elimination of most (but not all) of the implantation-induced point defects expanding the crystal lattice. The InGaN QWs were almost identical to those grown on unimplanted GaN substrates. In the next step of the experiment, we annealed samples grown on unimplanted and implanted GaN at temperatures of 900 °C, 920 °C and 940 °C for half an hour. The samples were examined using Photoluminescence, X-ray Diffraction and Transmission Electron Microscopy. We found out that the decomposition of InGaN QWs started at lower temperatures for the samples grown on the implanted GaN substrates what provides a strong experimental support that point defects play important role in InGaN decomposition at high temperatures.

Stability and mobility of native point defects in AlH3

2011 ◽  
Vol 509 ◽  
pp. S658-S661 ◽  
Author(s):  
Lars Ismer ◽  
Anderson Janotti ◽  
Chris G. Van de Walle
Keyword(s):  
Point Defects ◽  
Native Point Defects

Hg1-xCdxTe: Defect Structure Overview

1990 ◽  
Vol 216 ◽  
Author(s):  
M.A. Berding ◽  
A. Sher ◽  
A.-B. Chen
Keyword(s):  
Point Defects ◽  
Defect Structure ◽  
Defect Formation ◽  
Activation Energies ◽  
Mass Action ◽  
Native Defect ◽  
Native Point Defects ◽  
Vacancy Migration ◽  
Formation Energies ◽  
Diffusion Activation

ABSTRACTNative point defects play an important role in HgCdTe. Here we discuss some of the relevant mass action equations, and use recently calculated defect formation energies to discuss relative defect concentrations. In agreement with experiment, the Hg vacancy is found to be the dominant native defect to accommodate excess tellurium. Preliminary estimates find the Hg antisite and the Hg interstitial to be of comparable densities. Our calculated defect formation energies are also consistent with measured diffusion activation energies, assuming the interstitial and vacancy migration energies are small.

Correlation between Room Temperature Photoluminescence and Resistivity in Semiinsulating Silicon Carbide

2006 ◽  
Vol 527-529 ◽  
pp. 717-720 ◽  
Author(s):  
Sashi Kumar Chanda ◽  
Yaroslav Koshka ◽  
Murugesu Yoganathan
Keyword(s):  
Low Temperature ◽  
Point Defects ◽  
Room Temperature ◽  
Vanadium Content ◽  
Mapping Technique ◽  
Native Defect ◽  
Room Temperature Photoluminescence ◽  
Native Point Defects ◽  
Pl Mapping ◽  
Resistivity Variation

A room temperature PL mapping technique was applied to establish the origin of resistivity variation in PVT-grown 6H SiC substrates. A direct correlation between the native defect-related PL and resistivity was found in undoped (V-free) samples. In vanadium-doped samples with low vanadium content, the resistivity showed a good correlation with the total PL signal consisting of contributions from both vanadium and native point defects. Well-known UD1 and UD3 levels were revealed by low-temperature PL spectroscopy. Some correlation was observed between these low-temperature PL signatures and the resistivity distribution.

Effects of ternary additions on the deformation behavior of single crystals of MoSi2

2000 ◽  
Vol 646 ◽  
Author(s):  
Haruyuki Inui ◽  
Koji Ishikawa ◽  
Masaharu Yamaguchi
Keyword(s):  
Yield Strength ◽  
Strain Rate ◽  
Single Crystals ◽  
Creep Strain ◽  
High Temperatures ◽  
Low Temperatures ◽  
Deformation Behavior ◽  
Creep Strain Rate ◽  
Compression Creep ◽  
Ternary Additions

ABSTRACTEffects of ternary additions on the deformation behavior of single crystals of MoSi2 with the hard [001] and soft [0 15 1] orientations have been investigated in compression and compression creep. The alloying elements studied include V, Cr, Nb and Al that form a C40 disilicide with Si and W and Re that form a C11b disilicide with Si. The addition of Al is found to decrease the yield strength of MoSi2 at all temperatures while the additions of V, Cr and Nb are found to decrease the yield strength at low temperatures and to increase the yield strength at high temperatures. In contrast, the additions of W and Re are found to increase the yield strength at all temperatures. The creep strain rate for the [001] orientation is significantly lower than that for the [0 15 1] orientation. The creep strain rate for both orientations is significantly improved by alloying with ternary elements such as Re and Nb.

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